There are certain monsters you cannot make through combinations and must get through discs. They usually have a unique look, relating to the disc they have been spawned from:
 
Name Type Media Disc
Ambush Henger/??? DVD AI: Artificial Intelligence
ChaosDurahan Durahan/??? DVD Lord Of The Rings: The Two Towers (Special Features Disc)
ComedyKoro KoroPendora/??? DVD Simpsons Season 1 (Disc 1)
Devi Mocchi/??? PlayStation game Monster Rancher 2
Dino Zuum/??? PlayStation game Monster Rancher 1
Dolaine Antlan/??? PlayStation2 game Kingdom Hearts
Drividillo Madillo/??? PlayStation2 game Midnight Club 2
Drividillo Madillo/??? PlayStation2 game Gran Turismo 3
FakeGraffiti Zan/??? DVD The Simpsons Season 2 (Disc 1)
Goku Garu/??? PlayStation2 game Dragon Ball Z Budokai
GuanYuDuck Ducken/??? PlayStation2 game Grand Theft Auto 3
Guanyuduck Ducken/??? PlayStation2 game Grand Theft Auto Vice City
HipMew Mew/??? DVD Cowboy Bebop: The Movie
Joker Joker/Joker CD Silent Hill 3 soundtrack
Joker Joker/Joker DVD Terminator 3: Rise Of The Machines
Kagemusha Duran/??? PlayStation2 game Omnimusha 2
Kasumi Pixies/??? PlayStation2 game Kasumi
Miku Pixe/??? PlayStation2 game Fatal Frame
MushTan Plant/??? PC game Most computer games
Nightsickle Ripper/??? PlayStation2 game Final Fantasy 10
Kirin Zumm/??? PlayStation2 game Dynasty Warriors 4
PandiBaku Baku/??? DVD Shrek (Disc 1)
Phoenix DVD Dragon Ball Z Majun Buu- Defiance
White Mocchi Mocchi/??? DVD Ice Age